An assault rifle is a selective-firearm, meaning that the user can select between semi-automatic and automatic firing modes. The assault rifle usually has firearm cartridges with a detachable magazine. Assault rifles were first used during World War II and, by the end of the 20th century, had become the standard service rifle for most of the world's armies.
Until today, different types of assault rifles have been produced over the years. However, the majority of users still prefer the “old” reliable rifles withstanding the test of time, such as the AK-47 (from 1947, manufactured by “Kalashnikov Concern”) and the M16 (from 1957, manufactured by “Colt's Manufacturing Company”) rifles. These firearms are designed for, and were proven to operate in, extreme harsh conditions and have therefore become so popular.
As the security challenges of the 21st century differ from the challenges of the 20th century, alongside with the vast technological developments, these “old” rifles are required to operate in rather new situations and conditions. For instance, some armies are interested in usage of reliable firearms, such as the AK-47, as well as using new technology such as infrared sights or grenade launcher assemblies.
Therefore, a need arises for a way to modify (or upgrade) the old existing assault rifles so as to create a new firearm that combines the long-tested reliability of the “old” weapon with steady combat operation including enhanced capabilities.